code: def __len__(self):
      # You should change 0 to the total size of your dataset.
      return 0
  
file_path: pytorch-tutorial/tutorials/01-basics/pytorch_basics/main.py
imports: import torch
  import torchvision
  import torch.nn
  import numpy
  import torchvision.transforms
label_desc: Use image node_id 3 for calling the CustomDataset obj's underlying member method code with example usage: obj.__len__() and returns: int